GUT microbiota dysbiosis is a potential contributor to the development of diabetic retinopathy (DR), according to a 2026 systematic review and meta-analysis.
Microbial imbalance in the gut, known as dysbiosis, might contribute to escalating incidences of DR, via the gut-eye axis.
Diabetes and the Gut-Eye Axis
Following an annual increases in cases, the WHO predicts that one in 10 people living in the WHO European Region will have diabetes by 2045. DR, a vision-threatening condition in patients with diabetes, is a leading cause of preventable vision impairment in adults aged 20-74 years.
Diabetes is a primary factor influencing changes in the gut microbiota. Previous research has highlighted the “complex interplay” between gut dysbiosis and eye disorders.
Emerging evidence supports a gut-eye axis, a bidirectional pathway by which microbiota in the intestine influence ocular health through systemic inflammation, effects on vascular integrity, and metabolites crossing the intestinal barrier.
Changes in the Gut and Diabetic Retinopathy
The systematic review and meta-analysis examined 18 studies including observational, cohort and Mendelian randomisation designs.
The analysis found no significant differences in gut microbial alpha diversity, a measure of microbiome diversity applicable to a single sample, between patients with DR, patients with diabetes, and healthy controls.
However, beta diversity analyses consistently showed a “distinct clustering of microbial communities” between the above populations.
These findings suggested that gut dysbiosis exacerbates DR through the translocation of pro-inflammatory metabolites that can damage nerve cells in the retina.
Limitations
A key limitation of the meta-analysis was inconsistency observed in several alpha diversity measures.
Predominantly Asian cohorts were included in selected studies, so demographic biases are a consideration. Methodological variations also pose challenges for generalisability.
Clinical Implications for Diabetic Retinopathy
The findings affirmed gut dysbiosis as a factor in DR, with the gut-eye axis offering a potential mechanism linking diabetes and ocular health.
Researchers highlighted clinical interventions including dietary alterations, probiotics, or faecal microbiota transplantation to mitigate dysbiosis.
References
Sadeghi R et al. The gut–eye axis: microbiota and their role in diabetic retinopathy: a systematic review and meta-analysis. BMC Opthalmol. 2026;26(7). DOI: 10.1186/s12886-025-04599-3.
Zheng W et al. Gut-Eye axis. Adv Opthalmol Pract Res. 2025;5(3):165-174.
